Fuel cell stack structure

Abstract

The invention relates to a fuel cell stack structure capable of suppressing a drop in voltage resulting from flooding or contamination at an end in a direction in which cells are laminated, particularly in a cell at a gas outlet/inlet end. In this fuel cell stack structure, a layer which is irrelevant to power generation and in which a gas flow channel is formed is provided at least at a gas outlet/inlet end of a laminated-cell body of a fuel cell such as a solid-polyelectrolyte fuel cell. The layer is constructed of a dummy cell having a gas flow channel but no MEA. In addition, according to this fuel cell stack structure, both a fuel gas flow channel and an oxidative gas flow channel are formed in one face of the layer which is irrelevant to power generation and in which the gas flow channels are formed.

1. A fuel cell stack structure comprising:
 a laminated-power generation cell body constructed by laminating a predetermined number of power generation fuel cells, each having a membrane-electrode assembly and a separator, the separator has a gas flow channel and a gas manifold which connects between gas flow channels of different power generation fuel cells of the predetermined number of power generation fuel cells, and feed and exhaust pipes being provided on only one-side end of the laminated-power generation cell body, gas is supplied to the laminated-power generation cell body through the feed pipe, and gas discharged from the laminated-power generation cell body flows through the exhaust pipe, and 
 a gas flow channel layer having two faces which is provided outside of the laminated-power generation cell body, the gas flow channel layer being provided between the laminated-power generation cell body and a end plate, and communicates between the feed and exhaust pipes, the laminated-power generation cell body having a power generation portion; 
 wherein the gas flow channel layer is a layer which has no membrane-electrode assemblies, which communicates between an inlet side and outlet side of a fuel gas manifold of the separator, and communicates between an inlet side and outlet side of a gas manifold of the separator, 
 wherein both a fuel gas flow channel and an oxidative gas flow channel are formed in only one face of the gas flow channel layer, and 
 wherein condensate originating from the feed pipe flows into the gas flow channel. 
 
     
     
       2. The fuel cell stack structure according to  claim 1 , wherein the power generation fuel cells are a solid-polyelectrolyte fuel cell. 
     
     
       3. The fuel cell stack structure according to  claim 1 , wherein the gas flow channel layer is provided at either end of the laminated-power generation cell body. 
     
     
       4. The fuel cell stack structure according to  claim 1 , wherein the gas flow channel layer having no membrane-electrode assemblies is composed of a plurality of layers. 
     
     
       5. The fuel cell stack structure according to  claim 1 , wherein the fuel gas flow channel and the oxidative gas flow channel are not in contact with a membrane-electrode assembly. 
     
     
       6. The fuel cell stack structure according to  claim 1 , wherein a coolant flow channel is formed in one face of the gas flow channel layer having no membrane-electrode assemblies. 
     
     
       7. The fuel cell stack structure according to  claim 1 , wherein the gas flow channel layer is conductive. 
     
     
       8. The fuel cell stack structure according to  claim 1 , wherein the gas flow channel layer is made of carbon. 
     
     
       9. The fuel cell stack structure according to  claim 1 , wherein the gas flow channel layer traps condensate of humidified gas and impurities which are flowing from the feed pipe into the gas flow channel layer. 
     
     
       10. The fuel cell stack structure according to  claim 2 , wherein the power generation fuel cells are a solid polyelectrolyte fuel cell having a platinum catalyst. 
     
     
       11. The fuel cell stack structure according to  claim 1 , wherein the feed pipe includes inlet and outlet gas feed lines fluidly communicating with an upstream side of the power generation fuel cells. 
     
     
       12. A fuel cell stack structure comprising:
 a laminated-power generation cell body constructed by laminating a predetermined number of power generation fuel cells, which has a membrane electrode assembly and a separator, and feed and exhaust pipes being provided on only one-side end of the laminated-power generation cell body, gas is supplied to the laminated-power generation cell body through the feed pipe, and gas is discharged from the laminated-power generation cell body flow through the exhaust pipe; and 
 a gas flow channel having two faces which is provided between a end plate and the laminated-power generation cell body, the gas flow channel communicates between the feed and exhaust pipes; 
 wherein both a fuel gas flow channel and an oxidative gas flow channel are formed in only one face of the gas flow channel layer, and 
 wherein condensate originating from the feed pipe flows into the gas flow channel. 
 
     
     
       13. The fuel stack structure according to  claim 12 ,
 wherein the gas flow channel connects the inlet gas manifold and the outlet gas manifold outside of the laminated power generation cell body. 
 
     
     
       14. The fuel stack structure according to  claim 12 ,
 wherein the gas flow channel is formed in the direction of a plane of the membrane electrode assembly of the power generation fuel cells.